Track-door-lifting device



Oct. 15, 1929. R. E. JONES ET AL TRACK DOOR LIFTING DEVICE Filed Feb. 10, 1928 2 Sheets-Sheet 1 Richard EJZmes Oren E BaZtzZey.

almanac TRACK DOOR LIFTING DEVICE Filed Feb. 10, 1928 2 Sheets-Sheet 2 avwentom Kichard Edimes Oren F50 Z'b'ZZey attouwy Patented Get. 15, 1929 U o STATES PATENT OFFICE RICHARD E. Jones ANDOREN r. B Lrznn or HAGERSTOWN, MARYLAND, ASSIGNORS TO VICTOR oooLnn noon COM ANY, OF HAGEBSTOWN, MARYLAND TRACK-DQORLIFTIN G DEVIGE Application filed February 10, 1928. Serial No. 253,442.

The present invention relates in general to door operating systems for cold storage plants and the like requiring the use of a main door and a track door above the main door to be automatically opened and closed with the opening and closing of the main door, and

relates more specifically to operating mechanism for such an arrangementof doors.

The majority of devices of the above .general type at present available require the use of a substantially constant or continuous con.- nection between the track door and the main door for holding the track door open as long as the main door stays open, or require the use of operative connections which must vary in their proportions or size according to the size of the main door with which they are to be used. The first mentioned class, that involving constant or continuous connection, has the objection that as the position of one door is constantly'dependent on that .of the other, very careful initial adjustment is essen: tial to proper operation and any lack of adjustment or the development of lost motion between the parts due to wear, will result in faulty operation. which the dimensions must bear a. definite proportion to the size of the main door, has the commercial disadvantage that different sizes are required for different size doors thereby rendering them less suitable to quantity production and itsobvious advantages.

The chief object of the present invention is to obviate the above objections by the provision of .a door operating device operable to move the track door into full open and closed positions in a given small portion of the opening and closing movement of the main door intermediate the extreme open and closed positions of the main door; independently of a wide margin of lost motion or variation in adjustment between the parts carried by the difierent doors, and independently of the dimensions of the main door, thus enabling the mechanism to be constructed as a ;unit standard for doors of various sizes.

Another object is to provide a unit of the above type standard for both right and left hand doors, positive in its action, and opera- The latter class, that in ble with a minimum of friction and without strain on the main door or its hinges.

Another object is to provide an operating unit of the present type especially applicable to vertically swinging track doors and operable to hold the track door open under its own weight after being opened by a P01? tion of the opening movement of the main door independently of further movement of the latter.

Other objects of the invention will be apparent from a perusal of the following specification and the drawings accompanying the same.

Our invention .is illustrated in the accompanying drawings in which:

Fig. 1 is a front viewof the track door lifting device showing the track door and a portion of-the associated main door.

Fig. 2 is a vertical cross sectional view taken on. the line 2-2 of'Fig. 1 showing the maindoor and front wall of the refrigerator compartment in section and the track door and operating mechanism in full side view.

Fig. .3 is a fragmentary plan view showing connection 26.

Referring to the drawings in detail, 1 indicates a portion of the front wall ofarefrigerator or beef cooler having a main door 2 overlapping the edges of themain door open.- ing, the upper edge of which opening is indicate'd at;3, and a track door etoverlapping the track door opening 5, the track door being provided with a filler portion 8, most clearly shown in 'the'raised dotted line position at top of Fig. 2, which filler portion fits into the track door opening. As shown in dotted lines in Fig. 1, the track door opening extends down to the main door opening, and is of sulficient size to afford ample clearance above and at the sides-of the track 6'-for the passage of the beef hook travellers not shown and which may be ofany known or other suitable form. Because of the large size of the main door 2 in proportion to that of the track door 4 ion large proportions. As the track door opening extends down to the top edge 3 of the main door opening, the lower portion 7 of the tiller portion 8 is overlapped by the main door 1 as indicated in dotted lines in Figs. 1 and 2. This overlapping is to insure a com plete closure of the track door in a reliable and practical manner as will later appear.

The track door is provided with a loop hole 9 to accommodate the track 6 and is hingedly secured to the front of the refrigerator chamber above the track door opening by means of its operating shaft 10 to which it is fixedly secured by lugs 11, the shaft having bearing.

in the bearings 12 and a bearing 13 in the upper portion of the V-shaped bracket 14, bearings 12 and bracket 14 being secured to the front wall of the chamber.

At the apex of the V-shaped bracket 14 is a pair of pivot lugs 1516 bored to receive a pivot shaft 17 fixed therein and on which shaft is pivotally mounted the trip lever 18. The crank arm 19 arranged to be moved with the trip lever 18 preferably by forming it as a part thereof as shown, forms the lower link of a toggle lever 20, the upper link 21 of which is pivoted at 22 to a crank arm 23 fixed on the horizontal operating shaft 10, the adjacent ends of the toggle links being pivoted at 25. There is thus formed a toggle lever connection between the trip lever 18 and the operating shaft crank arm 23 in which the central pivot 25 may be thrown to either side of the dead-center line connecting the three pivotal points 1722-25in the straightened position of the toggle. As the weightof the track door 4 exerts a thrust along this line when in the open position (shown in dotted lines'in Fig. 2), this linkage forms an offcenter device tending to remain in the offcenter position into which it is last thrown. In Fig. 2 the toggle is shown in solid lines in one ofi-center position, the near side or forward position, which is the position assumed when the track door is closed; and is shown in dotted lines in the far side, off-center position which is that assumed when the track door is open. The upper part of the connection 26 (Figs. 2 and 3) between the pivot lugs 15 and 16 provides a stop member engaged by the arm19 when the toggle is straightened to lift the track door and then thrown slightly to the far side of dead center as shown in dotted lines in Fig. 2. I

To aid in moving the toggle to the off-center position, especially the far position or that to which it is moved in lifting the track door, a-retractile spring 27 is provided which is connected between the right hand end (Fig. 2) of the lower arm of the bracket 14 and the toggle link 21 in a manner to tend to draw the center of the toggle 'to the far side of the dead-center position against the stop 16.

For actuating the trip lever 18, a'trip bar 28 carried by a bracket 29 is secured to the main door 2 by screws 30 or other suitable securing means, in the position shown which is such that the trip bar 28 will be normally out of engagement with the trip lever 18, as clearly shown in Fig. 2, but during opening of the main door will swing through a horizontal plane into engagement with the trip lever to swing the trip lever into the dotted line position (Fig. 2) and thereafter move out of engagement with the trip lever in the continued opening movement of the main door.

In operation, starting with the parts in the position shown in Fig. 1, and in the solid line position shown in Fig. 2, the track door 4 is held closed through the overlapping of the lower end 7 of the filler portion 8 by the top of the main door 2, independently of the mechanism for operating the track door by the main door, the trip bar 28 being at this time wholly out of engagement with the trip lever 18. 7

As the main door is swung into open position, its top portion swinging away from the lower end 7 of the filler portion 8 of the track door, frees the track door after which the trip bar 28 swinging with the main door through a horizontal plane engages the trip lever 18 swinging it into the position shown in dotted lines in Fig. 2, the bar 28 then passing on out of engagement with the trip lever in the further opening movement of the main door. As the trip lever 18 is swung to the dotted line position (Fig. 2) the crank arm 19 carriedthereby and forming the lower link of the toggle 20 is swung to the right, throwing the toggle lever 20 and with it the track door 4 into the position shownin dotted lines in Fig. 2. As in this position the'central pivot 25 is at the far side of the dead-center, the arm 19 is held against st-op16 by the weight of the door, the retractile spring 27 tending to hold the toggle in the dotted line position against displacement by jar or vibration.

When the main door is closed, the trip bar 28 returning engages the trip lever 18 swinging it back to the right, which swings the crank arm 19 and with it the central pivot 25 to the near side of the dead center after which the weight of the track door aids in returning it and the parts connected therei with to the position shown in solid lines. After swinging the trip lever 18 back to the SOllCl line position, the trip bar 28 returns to the solid line position in the further movecompletely open and close the track door during a relatively small portion of the opening and closing movements, respectively, of the main door intermediate the full closed and open positions of the main door.

The forked end of the trip lever 18 is so shaped in relation to the horizontal path of the trip bar 28 that in normal operation they will act to positively move the track door into open and closed positions. However, due to the off center, snap movement effect of the toggle lever acted upon by the weight of the track door and the tension of the retractile spring, the track door and the parts connected therewith will be urged into the final open or closed position even should the trip lever and trip bar, through lack of adjustment or lost motion due to wear, fail to positively move the track door to the final positions.

While we have herein shown and described a specific form of our invention for the sake of a clear disclosure, it is to be understood that the invention is not limited to the speoific embodiment disclosed but contemplates all such variants and modifications thereof as fairly fall within the scope of the appended claims.

Having thus described our invention what we claim and desire to secure in Letters Patent is:

1. The combinationwith a storage chamber having a main door opening with a main door therefor and a trackway opening with a track door therefor, of an operating lever for the track door for opening and closing the same, and means operable in the opening and closing of the main door to engage said lever to completely open and close the track door during a portion of the opening and closing movement respectively of the main door between the fully closed and open positions of the main door.

2. A closure system for storage compartments comprising a main door opening, a track door opening above the main door opening, a door for the main opening, a vertically swinging track door for the track opening hinged above the track opening to swing vertically outwardly and upwardly, means for lifting said track door into open position, and operating means for said lifting means carried by the main door normally out of engagement with said lifting means in the closed position of the main door.

3. A device for opening and closing a track door in response to the opening and closing of a main door hinged to swing in a horizontal plane, comprising an operating lever for the track door arranged to swing in a vertical plane above the top edge of the main door, and a trip bar for the lever arranged to be mounted on the main door in a horizontal position with its path of travel intersecting the path of travel of the lever, whereby the path of travel of the point of contact between said lever and bar during engagement will move through the same straight line for different distances of the axis of the main door hinge from said lever, and the device rendered capable of use with main doors of different dimensions without change in dimension or proportions of the device.

l. In a storage chamber, a main door opening, a track door opening above the main door opening extending down to the upper edge of the main door opening, a track door having a portion arranged to close the track door opening down to the upper edge of the main'door opening, a main door arranged to close the main door opening and to overlap the top edge thereof and the lower end of said portion of said track door, and means for opening and closing said track door in response to the opening and closing of the main door operable to move the track door toward its open position only after a substantial amount of opening movement of the main door and to close the track door substantially in lead of the closed position of the main door in the closing movement of the main door.

5. In a substantially air tight compartment having a main door opening and a track door opening with a main door and a track door for said openings respectively, a shaft upon which the track door is mounted, offcenter actuating means for the shaft arranged to be tripped from one to the other of its off-center positions, and tripping means for said off-center means connected with the main door and arranged to engage the offcenter means only during a partly open position of the main door.

6.. The combination with a hinged main. door and a vertically swinging track door hinged at the top, of a normally bent toggle lever arranged to raise the track door into open position in straightening and to move beyond its dead center position, stop means for stopping the movement of the toggle lever at a point slightly beyond its dead center position, and means carried by the main door arranged to move said toggle lever beyond its dead center position in the opening movement of the main door and to trip the toggle lever to the near side of its dead center position during closing movement of the main door.

7. The combination with a main door and a track door, of a horizontal operating shaft on which the track door is mounted to swing into open and closed positions, a crank arm fixed on said shaft, bearings for said shaft, a bracket arranged in fixed relation to said shaft bearings, a trip lever pivoted on the bracket to swing about an axis parallel to said shaft, motion transmitting connections between said lever and the shaft, and a trip no. s.

carried by the main door, said lever being arranged to be engaged by said trip only while the main door is partly opened.

8. The combination with a main door and a vertically swinging track door hinged at the top, of a toggle lever arranged to raise the track door against the force of gravity into open position and to lock itself under weight of the track door in raised position, a trip carried by the main door arranged to move the toggle toward the locked position during opening movement of the main door and to trip the toggle out of locking position during the closing movement of the main door.

9. The combination claimed in claim 8 with tension means arranged to urge the toggle toward locked position.

10. Mechanism for operating a track door in response to the operation of a main door, comprising a horizontal shaft on which the track door is mounted to swing into open and closed positions, bearings for said shaft,

a bracket in which said shaft has bearing arranged to be mounted above the main door, a trip lever pivoted on said bracket to swing about an axis parallel to the shaft and arranged to extend downwardly toward, but above the top edge of the main door, a crank arm fixed on said horizontal shaft, a toggle lever connecting the trip lever With the crank arm having the extreme end of one of its link members pivoted to the end of said crank arm and the extreme end of the other link member pivoted concentrically with and arranged to be moved by said trip lever, the several parts being so arranged that with the track door closed the toggle is bent with its middle pivot out of the center line between the two extreme pivots, and that movement of the toggle into the straight position will rotate the crank arm to raise V the track door into open position against the force of its weight, a stop arranged to hold the toggle against further movement beyond the dead center line after the center pivot has passed slightly beyond the dead center to thus hold the toggle looked under the weight of the track door, and a horizontal trip bar separate from all the first mentioned elements arranged to be connected with the main door for movement thereby into operative engagement with the trip lever to actuate the toggle lever.

In testimony whereof we aflix our signatures. v

RICHARD E. JONES. OREN F. BALTZLEY. 

